Trouble with CYA

[Metalmushpuff]

I did my first tests with the TF Pro Salt on 2/24 and got a result of 50 for CYA. Sunday evening, I put 1lb of Suncoast stabilizer in a sock and floated it in my skimmer ( I realize now I probably should have put it in front of a return, but call it lesson learned). It was all dissolved by the next day. I just tested CYA again and got the same result of 50. What am I doing wrong here? Should I wait and retest again tomorrow or just add another pound of stabilizer? I don’t want to overshoot it but this stabilizer doesn’t seem to be making a difference. The bag says 98% Cyanuric Acid Hydrate. I’m feeling lost here!

Thanks for any advice!!

 

[Texas Splash]

If you had the stabilizer in a sock THEN in the skimmer, that is fine. It dissolved before going to the filter. Now it appears that 1 lb of stabilizer is about 10 ppm worth of CYA for your size pool. Keep in mind the CYA test does have a +/- 10-15 ppm variance since it's a bit tricky, so it's possible either the first test number or this one were slightly different.

 

[reggiehammond]

If your pool is 11k gallons, 1lb shows about 11 CYA.

It's very likely that your CYA is stuck in your filter - I'd give it another 1-2 days and test again. Given the inaccuracy of the CYA test - if a portion of the 11 is bound up in your cartridge right now, it's not surprising you don't see it in the results.

It's better to trust that it's actually there, since you put it in, than to add more and hope for the best.

 

[Texas Splash]

Below in case it helps.

CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Use the mixing bottle to gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Recommend standing outside with your back to the sun and the view tube in the shade of your body at waist level. Then, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. To help the eyes and prevent staring at the dot, some people find it better to pour & view in stages. Pour some solution into the viewing tube, look away, then look back again for the dot. Repeat as necessary until you feel the dot is gone. After the first CYA test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, gently shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate your own CYA reading. Finally, if you still doubt your own reading, have a friend do the test with you and compare results.

 

[ajw22]

1 lb of stabilizer in your 11K pool will raise CYA by 11.

Given that the CYA test accuracy is +/- 10 ppm at best and we round up you may not see that small of an increase in testing.

10 ppm does not make a big difference. CYA 50 is as good as 60. Your CYA is somewhere around there and good enough.

 

[Metalmushpuff]

Below in case it helps.

CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Use the mixing bottle to gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Recommend standing outside with your back to the sun and the view tube in the shade of your body at waist level. Then, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. To help the eyes and prevent staring at the dot, some people find it better to pour & view in stages. Pour some solution into the viewing tube, look away, then look back again for the dot. Repeat as necessary until you feel the dot is gone. After the first CYA test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, gently shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate your own CYA reading. Finally, if you still doubt your own reading, have a friend do the test with you and compare results.

Thank you. I did follow those steps. My son and I actually mixed and tested two separate samples because we thought we may have been off on the first one. The only other factor, which may be playing a bigger part than I realize, is the time of day for the test. The test on 2/24 was at around 4:30/5 and the test today was at 2.

 

[Metalmushpuff]

1 lb of stabilizer in your 11K pool will raise CYA by 11.

Given that the CYA test accuracy is +/- 10 ppm at best and we round up you may not see that small of an increase in testing.

10 ppm does not make a big difference. CYA 50 is as good as 60. Your CYA is somewhere around there and good enough.

I was trying to nudge it up to 70 in advance of the season. I do expect it will drop due to replacing water from splash out and heavy rains. Is that unnecessary?

 

[ajw22]

I was trying to nudge it up to 70 in advance of the season. I do expect it will drop due to replacing water from splash out and heavy rains. Is that unnecessary?

Wait until it tests at 40 then push it up to 60-70.